Marilyn Ducksworth, who is 56 years old and worked for Penguin for 27 years, filed suit against her former employer yesterday. She resigned from her job last week because Penguin had purportedly been demoting and forcing out older employees in favor of younger people.

In her complaint, Ducksworth says the publisher ostracized her for protesting the discriminatory practices, diminished her executive responsibilities, dismantled her staff and interfered with her internal and external professional relationships. She claims one Penguin executive told her the publisher wanted employees who were “faster, stronger and more nimble because the older, slower version doesn’t work anymore.”

Penguin said in a statement that “it was Marilyn Duckworth’s decision to resign” and that the publisher “does not condone, nor was there, any age discrimination or retaliation involved in her decision to leave.”